Who Is Rey's Father?

Rey is the protagonist in the new Star Wars film, The Force Awakens. Rey's last name was never revealed in the movie, so we don't know who her parents are. She could follow the Skywalker line, be the daughter of the smuggler Han Solo, a descendant of Obi Wan Kenobi, or maybe the daughter of a character not introduced yet. Who do you think is Rey's father?